Have you read the Physics basics tutorial, specifically the section on manual movement & other behaviors? Using events or other behaviors to move or rotate physics objects causes them to "teleport" in the Physics simulation, and often this results in glitches or Construct 2 struggling to synchronise your manual changes with the physics simulation. To guarantee a stable simulation you must never alter a Physics object other than applying forces, impulses or torque. This is not a bug, it's impossible to make physics simulations work smoothly when events are constantly altering the physics objects.